USMLE Question about HIV gp120/gp41 protein

[squintypanda]

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On first aid (2014 p. 167) it says HIV gp120/gp41 proteins are formed from env gene -> gp160 -> cleaved to gp120/gp41. However it also says that p120/gp41 are acquired through budding from host cell plasma membrane.

So which is it? or is it both? could someone explain the mechanism to me? thanks!

 

[Robotic Dock]

gp 120 and 41 are products of the action of aspartame protease cleaving 160. This is part of maturation. Then they transferred to the surface of the contaminated cell. You can take advantage of these and make drugs like Enfuvirtide (fuzeon) against gp 41 or whatever you want.

 

[aspiringmd1015]

aspartame protease = protease, the enzyme which is targeted by the protease inhibitors(obviously) protease is involved in many cleaving reactions to generate the final formed protein of many protein products the HIV virus creates for itself. But specifically to your question, the newly assembled visions do acquire p160 when they bud from the host cell(macrophages, t cells, and other APC's i.e. any cell that has a cd4, ccr5/cxcr5 receptors) once it acquires this, the protease enzyme is used to cleave it into the final product of gp120 and gp 41. Hope that made sense, thats how I understand it at least. Also some extra info that i just read, the drugs which are used against gp41(fusion inhibitors) bind to gp41 instead of binding to gp120 because the amino acid sequence of gp120 mutates so frequently that creating a drug to target gp120 would be close to impossible bc of the rapid resistance that would develop.